In common design flows for mixed-signal ASICs, Simulink models are used as executable specifications. Based on these specifications, analog and digital components are directly implemented in mixed-signal design environments. This step constitutes a large leap of abstraction. In this presentation, we address this aspect by showing and discussing an approach for automated transitions from Simulink models representing analog and digital components to HDL descriptions using Simulink HDL Coder™. The analog Simulink models are translated into continuous-value discrete-time HDL descriptions and can serve as reference behavioral models in the mixed-signal design environment. For digital Simulink components, we integrated custom modeling guidelines into Simulink Model Advisor for achieving HDL descriptions that are optimized with respect to area and power consumption. An evaluation of the presented design flow is shown by applying the flow to an automotive hardware design.